The present invention relates to office furniture and, more particularly, to adjustable chairs of the type including a base or pedestal, a back and a chair control for pivoting the back to the base.
A wide variety of adjustable office chairs are presently available which adapt to the particular user and task involved. Tilt back chairs include a chair control which permits the back to tilt or move from a fully upright to a fully inclined or reclined position. Provision may be made for preventing tilting of the chair back with respect to the base or seat. In addition, a variable stop mechanism may be included which provides a variety of maximum tilt positions. Adjustability of the degree of tilt of the back adapts the chair to the particular task and/or the user. Examples of chairs including variable stop or lock mechanisms may be found in commonly owned U.S. Pat. No. 4,720,142 entitled VARIABLE BACK STOP, which issued on Jun. 9, 1988 to Holdredge; commonly owned U.S. Pat. No. 4,494,795 entitled VARIABLE BACK ADJUSTER FOR CHAIRS, which issued on Jan. 22, 1985 to Roossien; and commonly owned U.S. Pat. No. 4,390,206 entitled SYNCHROTILT CHAIR CONTROL, which issued on Jun. 28, 1984 to Faiks et al.
The variable back stop mechanism disclosed in the aforementioned U.S. Pat. No. 4,720,142 includes a stop bracket connected to the chair support or base. A plurality of stop plates are provided in a stacked arrangement. The stop plates are carried by the chair back. Selected ones of the plates are moved forward when the chair back is moved to a desired stop or maximum tilt position. The degree of tilting or range of movement permitted is dependent upon the number of the stacked plates which have been moved forward. Thereafter, upon tilting movement from a fully upright towards a reclined position, the plates will contact the stop bracket on the chair support. Further tilting action is, therefore, prevented.
A need exists for an improved adjustable chair and variable back stop mechanism of reduced complexity than that heretofore available, which may be easily assembled or incorporated in a chair without changing or significantly modifying the parts of the chair, which is reliable in use and which may be manufactured and installed at reduced costs from that heretofore experienced.